The present invention relates generally to stormwater drainage structures and associated hardware, which are particularly suited for separation of contaminants from water. More particularly, the invention provides for a contaminant separating, filtering and absorbing apparatus that performs especially well in low flow areas with minimal available head pressure differential, such as small landscaped yards and small driveways and parking lots.
Drainage structures designed to collect stormwater runoff such as drainage inlet basins for roads and parking lots are widely known and used. Typically, the structure only provides the means to collect runoff from impervious or semi-impervious surfaces and direct the flow towards a system of pipes and/or tanks to convey and/or store the stormwater. Undesirable material added to the water during surface flow, either dissolved or suspended, such as oil, fuel, pesticides and the like, are transported within the drainage flow to the water body destination such as a lake or stream.
Recent concerns regarding water quality issues related to the stormwater runoff has prompted governmental regulation. The typical drainage structure does not remove or reduce the concentration of the undesirable material (contaminant). Therefore, requirements for supplemental devices designed to improve water quality, such as biofiltration swales, settling ponds, fluid/particle density separators, mechanical separators and media absorbers/filters now exist. The present invention can be classified as a stormwater quality-improving device combining fluid/particle density separation and media adsorption/filtration that is exceptionally suited for low flow applications.
The compact size, ease of operation and maintenance, low expense, and self contained design make this invention exceptionally suited for uses such as a filter system in a private yard. By installing a basic curtain drain system 9 and/or swale system to collect the yard runoff and using the system drain to feed the inlet pipe, the runoff can easily be treated for removal of applied fertilizers, herbicides, and pesticides. Additionally, runoff from driveways, impervious work areas and patios can be caught in basins, conveyed through solid pipe 43 to the inlet of the present invention, and treated for the removal of contaminants such as oil, gas, grease, and other related chemicals.